libext2fs: move the alignment field from unix_io to the io_manager

The align field which indicated the required data alignment of data
buffers was stored in a field specific to the unix_io manager.  Move
it to the top-level io_channel structure so it can be better
generalized.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/lib/ext2fs/ext2_io.h b/lib/ext2fs/ext2_io.h
index bcc2f87..95b8de3 100644 (file)
--- a/lib/ext2fs/ext2_io.h
+++ b/lib/ext2fs/ext2_io.h
@@ -58,6 +58,7 @@ struct struct_io_channel {
        long            reserved[14];
        void            *private_data;
        void            *app_data;
+       int             align;
 };
 
 struct struct_io_stats {

diff --git a/lib/ext2fs/test_io.c b/lib/ext2fs/test_io.c
index f67f6ae..7d3cdfe 100644 (file)
--- a/lib/ext2fs/test_io.c
+++ b/lib/ext2fs/test_io.c
@@ -247,6 +247,9 @@ static errcode_t test_open(const char *name, int flags, io_channel *channel)
        if ((value = safe_getenv("TEST_IO_WRITE_ABORT")) != NULL)
                data->write_abort_count = strtoul(value, NULL, 0);
 
+       if (data->real)
+               io->align = data->real->align;
+
        *channel = io;
        return 0;
 
@@ -292,8 +295,10 @@ static errcode_t test_set_blksize(io_channel channel, int blksize)
        data = (struct test_private_data *) channel->private_data;
        EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_TEST_IO_CHANNEL);
 
-       if (data->real)
+       if (data->real) {
                retval = io_channel_set_blksize(data->real, blksize);
+               channel->align = data->real->align;
+       }
        if (data->set_blksize)
                data->set_blksize(blksize, retval);
        if (data->flags & TEST_FLAG_SET_BLKSIZE)

diff --git a/lib/ext2fs/unix_io.c b/lib/ext2fs/unix_io.c
index da3f8fd..3269392 100644 (file)
--- a/lib/ext2fs/unix_io.c
+++ b/lib/ext2fs/unix_io.c
@@ -180,8 +180,9 @@ static errcode_t raw_read_blk(io_channel channel,
                retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
                goto error_out;
        }
-       if ((data->align == 0) ||
-           ((IS_ALIGNED(buf, data->align)) && IS_ALIGNED(size, data->align))) {
+       if ((channel->align == 0) ||
+           (IS_ALIGNED(buf, channel->align) &&
+            IS_ALIGNED(size, channel->align))) {
                actual = read(data->dev, buf, size);
                if (actual != size) {
                short_read:
@@ -250,8 +251,9 @@ static errcode_t raw_write_blk(io_channel channel,
                goto error_out;
        }
 
-       if ((data->align == 0) ||
-           ((IS_ALIGNED(buf, data->align)) && IS_ALIGNED(size, data->align))) {
+       if ((channel->align == 0) ||
+           (IS_ALIGNED(buf, channel->align) &&
+            IS_ALIGNED(size, channel->align))) {
                actual = write(data->dev, buf, size);
                if (actual != size) {
                short_write:
@@ -319,14 +321,15 @@ static errcode_t alloc_cache(io_channel channel,
                if (cache->buf)
                        ext2fs_free_mem(&cache->buf);
                retval = ext2fs_get_memalign(channel->block_size,
-                                            data->align, &cache->buf);
+                                            channel->align, &cache->buf);
                if (retval)
                        return retval;
        }
-       if (data->align) {
+       if (channel->align) {
                if (data->bounce)
                        ext2fs_free_mem(&data->bounce);
-               retval = ext2fs_get_memalign(channel->block_size, data->align,
+               retval = ext2fs_get_memalign(channel->block_size,
+                                            channel->align,
                                             &data->bounce);
        }
        return retval;
@@ -518,8 +521,8 @@ static errcode_t unix_open(const char *name, int flags, io_channel *channel)
 
 #ifdef BLKSSZGET
        if (flags & IO_FLAG_DIRECT_IO) {
-               if (ioctl(data->dev, BLKSSZGET, &data->align) != 0)
-                       data->align = io->block_size;
+               if (ioctl(data->dev, BLKSSZGET, &io->align) != 0)
+                       io->align = io->block_size;
        }
 #endif
 
@@ -534,7 +537,7 @@ static errcode_t unix_open(const char *name, int flags, io_channel *channel)
         * Some operating systems require that the buffers be aligned,
         * regardless of O_DIRECT
         */
-       data->align = 512;
+       io->align = 512;
 #endif
 
 
@@ -810,7 +813,7 @@ static errcode_t unix_write_byte(io_channel channel, unsigned long offset,
        data = (struct unix_private_data *) channel->private_data;
        EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
 
-       if (data->align != 0) {
+       if (channel->align != 0) {
 #ifdef ALIGN_DEBUG
                printf("unix_write_byte: O_DIRECT fallback\n");
 #endif